This project proposes to integrate theories of self and identify in order to examine adolescents' motivations about pregnancy and disease prevention. A multisite longitudinal study will be conducted over 2 years in health clinics throughout Connecticut. Three hundred pregnant and three hundred nonpregnant adolescents will be enrolled. Data will be collected every 6 months in face-to-face interviews and with urine STD testings. Measures of identity, HIV-related knowledge and attitudes, self-reported sexual behavior, nd subsequent STDs and pregnancy will be collected. This study will describe adolescents' sense of identify and the relationship to pregnancy and STD risk. Specifically, the strength of identity will be determined as well as risk factors that distinguish adolescents who are pregnant upon entering into the study. prospectively, the project will determine predictors of pregnancy and STDs in addition to predictors of the self-report of condom use and contraceptive choice. The unique contribution that sense of identity makes to these factors will be examined. The impact of the transition to motherhood on sexual behavior over time will be assessed. A second study within this project will enroll 200 hundred sexual partners and 200 parents. In this cross- sectional study, the relative strength of identities and attitudes between groups will be examined, as well as the impact of the interpersonal context on later condom use and contraceptive choices of the women.